Weather Blog: Cooler By The Lake Rules

Thank you for stopping by the Weather Watch 12 Blog! A rare dry stretch of weather will continue over southeastern Wisconsin into the middle of this week. As the dry weather takes hold the focus will shift to temperatures across the area. In today's blog we discuss the impact the lake breeze will have on highs the next several days and why the lake breeze forms.

Let's start with a gorgeous sunrise photo from Steve in Brookfield on Sunday morning. The photo includes a touch of fog and a colorful sky with cirrus clouds streaming through our area. Remember, if you have a weather photo to share we would love to see it! Steve's photo was featured on WISN 12 News this Morning! Just email your photo to ulocal@wisn.com or post to the Wisconsin Weather Updates Facebook page.

The next several days will feature quiet weather across our viewing area. The focus will shift to temperatures as wind direction and a lake breeze will keep a wide spread of temperatures in place from lakeshore locations to area well inland.

The main weather features impacting our weather in Wisconsin today through Tuesday will be high pressure sliding in from the west, and a slow moving low pressure area over the South and Southeast. With a clockwise flow around high pressure and counterclockwise around low pressure, the location of southeast Wisconsin in relation to the pressure areas will keep surface winds north or northeast.

The WPC surface forecast map shown below is valid Monday morning at 7am showing the high to our west, and low to the southeast.

With a north or northeast wind 'cooler by the lake' will rule through at least Tuesday. As temperatures warm Sunday, Monday, and Tuesday a lake breeze will enhance the already northeasterly component to the wind.

Here's how a lake breeze develops. High pressure is located over the cold waters of Lake Michigan. Inland, low pressure resides. As temperatures warm over the land a general rising motion is created with low pressure as the air is less dense. As air rises near the low, air over Lake Michigan begins to push over the land. Remember, air flows from high pressure to low pressure. The air over the lake is being refrigerated by the chilly waters and results in cooler temperatures near the lake as the wind moves the cooler air across land.

Here's an example from a temperature forecast valid at 3pm Monday. As a lake breeze forms on Monday, inland areas stay in the 66-72 degree range, with areas along the lake cooler in the 50s or 60s.

Most of the time a lake breeze will keep areas near the lake 5 to 15 degrees cooler than areas inland. If you have any questions regarding the lake breeze feel free to ask!

For the latest weather information watch WISN 12 News, and for updates throughout the day follow me on Twitter @jnelsonweather